Mercedes-Benz GLA 45 AMG 2014 Review

Mercedes-Benz GLA 45 AMG

Don't be misled: whichever way you cut it, the GLA 45 AMG is a bona-fide hot hatch.

At its heart is one of the world's finest 2.0-litre four-cylinder engines, with forged pistons, long-stroke cylinder dimensions and a twin-scroll turbo packing a hefty 1.8 bar of peak boost pressure helping to kick out no less than 265kW and a V8-like 450Nm everywhere between 2250 and 5000rpm.

The result is the sort of effortless mid-range urge you'd expect from an engine at least twice as big, a satisfying turbo rush that squeezes you firmly into the seats and a top-end power spread that extends well beyond most turbo engines.

This is a hot four par excellence, and – apart from its diet of 98 RON PULP – its only shortcoming is the inevitable lack of bottom-end torque anywhere under 2000rpm.

Also shared with the A 45 hatchback is Merc's first seven-speed dual-clutch automatic transmission, delivering lightning-quick up- and down-shifts, the latter accompanied by a hairy-chested exhaust bark in sport mode.

The downside, as with all twin-clutch auto-manuals, is that the AMG SPEEDSHIFT DCT isn't as smooth or progressive as a traditional torque-converter auto in low-speed use, like car parks and heavy traffic.

And there's the same permanent, sports-tuned 4MOTION all-wheel drive system, delivering outstanding levels of straight-line and cornering traction, and virtually eliminating unwanted torque back through the superbly weighted, pinpoint-precise Alcantara-clad three-spoke multifunction steering wheel.

There's even a launch control function, which is more complex to activate than others but delivers similarly spectacular results. Select manual transmission mode and sports traction control mode, pull and hold both paddle shifters then the right-side upshifter, then floor the throttle and release the brake.

As we discovered after repeated runs on a sweltering day at Sandown raceway, the upshot is a devastatingly effective standing-start getaway and confirmation the quickest GLA is indeed capable of hitting 100km/h in about 4.8 seconds.

That's rapid in anyone's language, and there's no arguing with an electronically-limited 250km/h top speed.

The only blight on this 45 AMG's racetrack performance was varying levels of front axle tramp as the front tyres scrambled for grip on the slick Sandown surface, before the traction control system directed torque to the rear-end near seamlessly time after time.

Mind you, the soft Continental ContiSport Contact front tyres on our test car were almost shredded at the end of a long, hard day at the track, preceded by a spirited drive through the ranges north east of Melbourne the previous day.

Surprisingly, as we discovered both on track and off, repeated hard braking – at least in the 30-degree heat we encountered on both days – led to worryingly loud brake-pad groan in both cars we drove.

But there's no question of the GLA AMG's sporting credentials, which include big, strong brakes and 20-inch alloys, stiffer and 25mm-lower suspension and a rigid, quiet body shell draped over Stuttgart's latest MFA platform, which underpins the A-, B-, CLA- and GLA-Class compacts.

As in the AMG versions of all those models (B-Class excluded), the cabin is tight and cosseting, providing only average rear-quarter vision from the hip-hugging, all-electric and heated AMG Performance front seats, the generous side bolstering of which make getting in and out just a little harder.

They look the part though, with red highlights on the perforated black leather upholstery matching the red seatbelts, standard-fit AMG Night Package cabin finishes, the full-house COMAND APS satellite-navigation and 12-speaker Harmon Kardon Logic 7 surround sound – all operated by a central console controller and 'floating' iPad-style dash screen.

Naturally, there's all the standard fare of regular GLAs, like a reversing camera, Collision Prevention Assist, Blind Spot Assist, Pre-Safe, Attention Assist, Active Bonnet, Active Parking Assist and dual-zone climate-control, plus Distronic Plus, Lane Keeping Assist, Intelligent Light System and a huge panoramic sunroof from the GLA 250.

Of course, the GLA wears completely different bodywork from the A-Class hatch and, although it shares the same 2699mm wheelbase, is also 150mm longer overall (4445mm), 80 litres larger in the boot (421 litres) and 37g heavier at 1585kg.

In a further attempt to differentiate its third MFA model (a fourth will come in the form of a CLA 'Shooting Brake' wagon), Benz has fitted all GLAs as standard with a powered tailgate, and the five-door/five-seat 'SUV' also scores the segment's obligatory matte-plastic body extensions.

Like all 45s, the AMG version has a 25mm lower ride height than its donor vehicle, meaning it now rides just 19mm higher than the A 45. If this is an SUV, as Mercedes insists, then the G-Class is a tractor.

Yet all this plus slightly softer suspension and slightly higher-profile 235/40 R20 rubber, which make the ride only a little more bearable on broken surfaces, dilutes the four-pot AMG experience in a small but noticeable way.

The GLA AMG feels a bit slower than the cracking A 45 because it is (by two-tenths to 100km/h) and is also less agile in corners, where the softer suspension and extra weight generates more weight transfer and a touch more understeer.

Sure, the sharp A 45 is a lofty yardstick and the GLA 45 is the sportiest 'SUV' this side of a Porsche Macan. It also makes its only direct rival – Audi's RS Q3 – look tame in comparison.

But the 'crossover' of AMG's smallest model family demands other concessions. It might undercut the RS Q3 by nearly $2500, but the GLA 45 is an expensive small car at just under $80,000.

That's nearly as much as the bigger base Macan and about $4500 more than the A 45 ($74,900), but still almost $7500 less than the CLA 45 sedan ($86,900).

And, although its longer roofline and more rounded rear-end make it significantly slipperier than the A 45 (which has a drag coefficient of 0.34Cd – versus 0.31), fuel consumption is incrementally higher (7.6 v 6.9L/100km), making the bigger GLA 45 more expensive to buy and run.

The flipside is more cargo space, more rear headroom (especially compared to the CLA) and marginally better ride comfort. The differences aren't significant, but the GLA is the most practical, most user-friendly member of the four-cylinder AMG range.

For many AMG-mad, SUV-obsessed Australians, it seems these subtle advantages outweigh the GLA 45's shortcomings, with demand already outstripping supply three to one.

Whether or not its popularity comes at the expense of the A 45, the hatch's status as the nation's top-selling AMG appears to be under serious threat from the hottest GLA.

If you're in the market for the most serious small SUV money can buy, look no further than the GLA AMG, but in reality it's a more practical – yet pricier – hot hatch alternative to the standard-setting A 45.

2014 Mercedes-Benz GLA 45 AMG pricing and specifications:
Price: $79,430 (plus on-road costs)
Engine: 2.0-litre four-cylinder turbo-petrol
Output: 265kW/450Nm
Transmission: Seven-speed dual-clutch auto
Fuel: 7.6L/100km (ADR combined)
CO2: 177g/km (ADR combined)
Safety rating: Five-star Euro NCAP